KUNMING, March 3 (Xinhua) -- Chinese authorities now face new challenges in countering terrorism as terrorist attacks have crossed the Xinjiang border years after 2009, when the worst riots in decades broke out in the region.

Tian'anmen, an iconic spot in the heart of Beijing, was a target in October and, months later, the Kunming railway station in the southwestern province of Yunnan became the prey.

The United Nations and many countries, including Russia, France, the United States, Japan and Germany, have denounced the brutal attack on civilians.

WHY KUNMING?

On Saturday night, a group of knife-wielding attackers slashed frantically at crowds at the Kunming railway station, killing 29 people and injuring 143.

Police shot dead four of them and captured an injured female attacker at the scene. Police said Monday that the remaining three suspects involved in the attack had been captured.

Authorities said evidence at the crime scene showed that the terrorist attack was orchestrated by Xinjiang separatist forces.

The separatist forces have also been blamed for a series of violent attacks mainly on police stations and government offices in Xinjiang in past years.

Why did they target Kunming? The question haunted many locals as well as people in other parts of the country when they learned about the shocking news.

Kunming, capital of Yunnan, is a major tourist destination known for its mild climate and perennial sunshine. Yunnan is home to more than 25 ethnic minorities whose population totals 15.5 million, accounting for one-third of the province's total.

Yunnan, which borders the notorious Golden Triangle, has become a major place for Xinjiang separatist forces to hide or sneak into neighboring countries and to join in jihad in the Middle East, according to police from Yunnan and Xinjiang.

In the face of tightening security in Xinjiang, the terrorists have chosen to strike outside of Xinjiang, police said.

Ahead of the two sessions of the national legislature and political consultative conference, Urumqi, capital of Xinjiang, and the national capital of Beijing have beefed up security measures, making Kunming and other cities seemingly much easier targets, said Li Wei, director of the security and arms-control research institute at the China Institute of Contemporary International Relations.

NEW CHALLENGES

The attacks in Beijing and Kunming have sent a clear signal that the terrorists are shifting to target civilians, and this underlines the need to set up a national security commission to meet new counterterrorism challenges, said experts.

The two attacks indicate an escalation and spillover of the violent terrorist activities in Xinjiang and they aimed to generate greater horror in the public, said Yang Shu, head of the Central Asia Institute of Lanzhou University.

Wang Dahao, a writer from Xinjiang who has written several review articles of his hometown, said that while separatists conducted terrorist activities in Xinjiang, they also were starting to generate an atmosphere of terror outside Xinjiang.

"In their eyes, terrorist attacks on civilians outside Xinjiang could have bigger influence worldwide and trigger bigger panic nationwide. This is what they want," Wang said.

Li said the Kunming violence sounded a warning that similar attacks could happen in other regions.

"Judging from the timing and how they conducted the killing spree, the terrorists made careful preparations and planning," said Li. "The attack came ahead of the two sessions and it indicated that they had clear political motives."

Zhao Gancheng, a counterterrorism expert with the Shanghai Institute for International Studies, said this kind of terrorist attack has seldom happened in China, except in Xinjiang.

The violence occurred at a big transport terminal in a bustling city, and this has put to test the Chinese government's response to major emergencies, Zhao said.

Zhao said China has set up a national security commission, and the latest terrorist attack means the commission has to act quickly.

To fight terrorism, the government should step up pre-warnings and precautions, but boosting the public's awareness in taking preventive measures is a long-term task, said Li.

Many warned that making sufficient precautions when terrorists target civilians is a daunting task.

"We have set up a national security commission, but what will the local governments do? How to integrate their security departments? How will we respond if similar attacks occur in other regions? These are some of the questions we need to think about," said Nian Da, a veteran in Kunming.

Meanwhile, the penetration of laptop computers, mobile phones and the Internet have made it easier to spread religious extremism and instigate violent crimes, according to police authorities in Xinjiang.

Xinjiang has been at the country's forefront against terrorism. Violent attacks have erupted periodically across the vast region over the past two decades. Experts say many are linked to a surge in religious extremism in the region.

On July 5, 2009, rock-flinging and knife-wielding thugs looted shops, torched vehicles and killed nearly 200 people in Urumqi. The government blamed overseas groups for inciting the riots.

Violent terrorist attacks have been increasing since 2009 and have become the biggest security threat to Xinjiang.

Some 190 terrorist attacks were recorded in Xinjiang in 2012, increasing by a significant margin from 2011, according to the regional public security department.